FOOD POISONING

Bacteria are everywhere – in the soil, water, dust and even
our bodies.They cannot be eliminated
totally.

Not all bacteria are harmful.For examples, some help to make cheese and yoghurt.

Bacteria need warmth, food, moisture and time to multiply.

Food poisoning bacteria grow best between 5-63°C.

Most bacteria are killed at temperatures of 70°C;
and bacteria do not grow or grow on slowly below 5°C. At very low
temperatures some bacteria will die, but many survive and grow again if warm
conditions return.

Food poisoning bacteria can be dangerous and can kill –
although this is rare.

The symptoms of food poisoning can last for days and include
abdominal pains, diarrhoea, vomiting, nausea and fever.The symptoms usually come on suddenly, but
can occur days after eating contaminated food.

Food poisoning bacteria are very hard to detect; they do not
usually affect the taste or smell of the food.

Young children, the elderly, the sick and pregnant women are
particularly vulnerable to food poisoning.

Use the links below to discover more about some of the
causes of food poisoning:

SALMONELLA

Source:Salmonella has been found in
raw meat, poultry and eggs, raw unwashed vegetables, unpasteurised dairy
products and many other types of food.It is found in the gut and excreta of animals and humans.

Characteristics:Salmonella remains dormant when
refrigerated but is destroyed by thorough cooking and pasteurisation.

Usually large
numbers of the bacteria are needed to cause infection but outbreaks have been
reported where the infective dose has been low.

Symptoms:The incubation period for Salmonella
food poisoning is between 12 and 72 hours.

Symptoms include
fever, diarrhoea, vomiting and abdominal pain.

Infection is
usually mild, although it can on occasion be very severe and on rare occasions
may be fatal.

Symptoms may last
up to seven days.

CAMPYLOBACTER

Source:Campylobacter can be found in raw
meat, poultry and excreta, untreated water and raw milk.

Milk can be
contaminated by birds pecking bottle tops on the doorstep.

Pets with diarrhoea
can be a source of infection.

Characteristics:The infective dose can be low.

Thorough cooking
and pasteurisation will destroy Campylobacter.

Symptoms:Symptoms include a period of fever,
headache and dizziness for a few hours, followed by severe abdominal pain and
diarrhoea which may be bloody.

Symptoms can take 1-11
days to appear and last between two and seven days and can recur over a number
of weeks.

STAPHYLOCOCCUS AUREUS

Source:Staphylococcus aureus may be
found on skin, in cuts and in the nose.It may also be found in unpasteurised
milk.

It can be
transferred to food from the hands or from droplets from the nose
or mouth.

Characteristics:Food poisoning from Staphylococcus aureus
follows the consumption of heavily contaminated food, where bacteria have
multiplied and produced a toxin which causes illness when the food is
consumed.

Staphylococcus
aureus is dormant when refrigerated.The bacterium is destroyed by pasteurisation and normal cooking,
however, the toxin may not be destroyed.

Characteristics:Bacillus
cereus can form spores when conditions are unfavourable for growth.

The spores are not easily
destroyed by heat and will survive cooking.If the food is cooled slowly or kept warm for some time before serving
they will germinate producing bacteria which multiply rapidly at these
temperatures and produce a very heat resistant toxin which will not be
destroyed by subsequent heating.

Symptoms:The incubation period for Bacillus
cereus food poisoning is between 1 to 5 hours.

Symptoms
include nausea, vomiting, diarrhoea and abdominal pain.

Onset of symptoms can be very
sudden, but it is usually over fairly quickly.It is unlikely to be fatal.

LISTERIA

Source:Listeria is an environmental
organism and can be found in soil, vegetation, raw milk, meat, poultry,
cheeses (particularly soft-ripened varieties) and salad vegetables.One type is Listeria monocytogenes.

It is found in the gut of
animals and humans, in sewage and throughout the environment.

Characteristics:Listeria, unlike most other food poisoning
bacteria, can grow at low temperatures even in the fridge.

Outbreaks occur
most frequently in nursing homes and hospitals due to person to person spread.

Symptoms:SRSvs cause an acute self-limiting
gastro-enteritis and are the commonest cause of epidemic viral
gastro-enteritis.

Symptoms include
vomiting and diarrhoea.

The incubation
period is 24-48 hours and infectivity lasts for 48 hours after the
resolution of symptoms.

E COLI

Source:E Coli is a widespread organism
and there are many different types.It
is normally found in the bowels of animals and humans.

One uncommon type which can
cause serious illness is Verocytotoxin producing E coli0157
which has been found in raw and under-cooked meats, unpasteurised milk and
dairy products, raw vegetables and unpasteurised apple juice.

Characteristics:The infective dose is low and a
small number of organisms can cause this illness.

It can survive refrigeration
and freezer storage but thorough cooking and pasteurisation will kill these
bacteria.Mince, sausages, burgers and
poultry should be cooked until they are piping hot throughout, the juices run
clear and not pink bits remain.

Symptoms:The
incubation period is 1-6 days.

Symptoms include diarrhoea,
which may be bloody, and can leads to kidney failure, and in some cases death.

The very young
(under 6) and elderly are particularly vulnerable.

CLOSTRIDIUM PERFRINGENS

Source:Clostridium
perfringens can be found in soil, excreta, raw meat and insects.

Characteristics:Clostridium perfringens can multiply during
slow low temperature cooking, warming up or long cooling periods, and is
particularly associated with gravies, cooked meat dishes, stews and pies and
very large joints of meat and poultry.

Clostridium perfringens produce spores
which may be killed during cooking andreheating.Food that is not to be eaten immediately
following cooking must be cooled rapidly then refrigerated to prevent the
spores germinating.

Symptoms:Symptoms are mainly abdominal pain,
diarrhoea and nausea after an 8-22 incubation period.